//
// Copyright(C) 1993-1996 Id Software, Inc.
// Copyright(C) 2005-2014 Simon Howard
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// DESCRIPTION:
//  Enemy thinking, AI.
//  Action Pointer Functions
//  that are associated with states/frames.
//

#include <stdio.h>
#include <stdlib.h>

#include "m_random.h"
#include "i_system.h"

#include "doomdef.h"
#include "p_local.h"

#include "s_sound.h"

#include "g_game.h"

// State.
#include "doomstat.h"
#include "r_state.h"

// Data.
#include "sounds.h"




typedef enum
{
    DI_EAST,
    DI_NORTHEAST,
    DI_NORTH,
    DI_NORTHWEST,
    DI_WEST,
    DI_SOUTHWEST,
    DI_SOUTH,
    DI_SOUTHEAST,
    DI_NODIR,
    NUMDIRS

} dirtype_t;


//
// P_NewChaseDir related LUT.
//
dirtype_t opposite[] =
{
  DI_WEST, DI_SOUTHWEST, DI_SOUTH, DI_SOUTHEAST,
  DI_EAST, DI_NORTHEAST, DI_NORTH, DI_NORTHWEST, DI_NODIR
};

dirtype_t diags[] =
{
    DI_NORTHWEST, DI_NORTHEAST, DI_SOUTHWEST, DI_SOUTHEAST
};





void A_Fall (mobj_t *actor);


//
// ENEMY THINKING
// Enemies are allways spawned
// with targetplayer = -1, threshold = 0
// Most monsters are spawned unaware of all players,
// but some can be made preaware
//


//
// Called by P_NoiseAlert.
// Recursively traverse adjacent sectors,
// sound blocking lines cut off traversal.
//

mobj_t*     soundtarget;

void
P_RecursiveSound
( sector_t* sec,
  int       soundblocks )
{
    int     i;
    line_t* check;
    sector_t*   other;

    // wake up all monsters in this sector
    if (sec->validcount == validcount
    && sec->soundtraversed <= soundblocks+1)
    {
    return;     // already flooded
    }

    sec->validcount = validcount;
    sec->soundtraversed = soundblocks+1;
    sec->soundtarget = soundtarget;

    for (i=0 ;i<sec->linecount ; i++)
    {
    check = sec->lines[i];
    if (! (check->flags & ML_TWOSIDED) )
        continue;

    P_LineOpening (check);

    if (openrange <= 0)
        continue;   // closed door

    if ( sides[ check->sidenum[0] ].sector == sec)
        other = sides[ check->sidenum[1] ] .sector;
    else
        other = sides[ check->sidenum[0] ].sector;

    if (check->flags & ML_SOUNDBLOCK)
    {
        if (!soundblocks)
        P_RecursiveSound (other, 1);
    }
    else
        P_RecursiveSound (other, soundblocks);
    }
}



//
// P_NoiseAlert
// If a monster yells at a player,
// it will alert other monsters to the player.
//
void
P_NoiseAlert
( mobj_t*   target,
  mobj_t*   emmiter )
{
    soundtarget = target;
    validcount++;
    P_RecursiveSound (emmiter->subsector->sector, 0);
}




//
// P_CheckMeleeRange
//
boolean P_CheckMeleeRange (mobj_t*  actor)
{
    mobj_t* pl;
    fixed_t dist;

    if (!actor->target)
    return false;

    pl = actor->target;
    dist = P_AproxDistance (pl->x-actor->x, pl->y-actor->y);

    if (dist >= MELEERANGE-20*FRACUNIT+pl->info->radius)
    return false;

    if (! P_CheckSight (actor, actor->target) )
    return false;

    return true;
}

//
// P_CheckMissileRange
//
boolean P_CheckMissileRange (mobj_t* actor)
{
    fixed_t dist;

    if (! P_CheckSight (actor, actor->target) )
    return false;

    if ( actor->flags & MF_JUSTHIT )
    {
    // the target just hit the enemy,
    // so fight back!
    actor->flags &= ~MF_JUSTHIT;
    return true;
    }

    if (actor->reactiontime)
    return false;   // do not attack yet

    // OPTIMIZE: get this from a global checksight
    dist = P_AproxDistance ( actor->x-actor->target->x,
                 actor->y-actor->target->y) - 64*FRACUNIT;

    if (!actor->info->meleestate)
    dist -= 128*FRACUNIT;   // no melee attack, so fire more

    dist >>= 16;

    if (actor->type == MT_VILE)
    {
    if (dist > 14*64)
        return false;   // too far away
    }


    if (actor->type == MT_UNDEAD)
    {
    if (dist < 196)
        return false;   // close for fist attack
    dist >>= 1;
    }


    if (actor->type == MT_CYBORG
    || actor->type == MT_SPIDER
    || actor->type == MT_SKULL)
    {
    dist >>= 1;
    }

    if (dist > 200)
    dist = 200;

    if (actor->type == MT_CYBORG && dist > 160)
    dist = 160;

    if (P_Random () < dist)
    return false;

    return true;
}


//
// P_Move
// Move in the current direction,
// returns false if the move is blocked.
//
fixed_t xspeed[8] = {FRACUNIT,47000,0,-47000,-FRACUNIT,-47000,0,47000};
fixed_t yspeed[8] = {0,47000,FRACUNIT,47000,0,-47000,-FRACUNIT,-47000};

boolean P_Move (mobj_t* actor)
{
    fixed_t tryx;
    fixed_t tryy;

    line_t* ld;

    // warning: 'catch', 'throw', and 'try'
    // are all C++ reserved words
    boolean try_ok;
    boolean good;

    if (actor->movedir == DI_NODIR)
    return false;

    if ((unsigned)actor->movedir >= 8)
    I_Error ("Weird actor->movedir!");

    tryx = actor->x + actor->info->speed*xspeed[actor->movedir];
    tryy = actor->y + actor->info->speed*yspeed[actor->movedir];

    try_ok = P_TryMove (actor, tryx, tryy);

    if (!try_ok)
    {
    // open any specials
    if (actor->flags & MF_FLOAT && floatok)
    {
        // must adjust height
        if (actor->z < tmfloorz)
        actor->z += FLOATSPEED;
        else
        actor->z -= FLOATSPEED;

        actor->flags |= MF_INFLOAT;
        return true;
    }

    if (!numspechit)
        return false;

    actor->movedir = DI_NODIR;
    good = false;
    while (numspechit--)
    {
        ld = spechit[numspechit];
        // if the special is not a door
        // that can be opened,
        // return false
        if (P_UseSpecialLine (actor, ld,0))
        good = true;
    }
    return good;
    }
    else
    {
    actor->flags &= ~MF_INFLOAT;
    }


    if (! (actor->flags & MF_FLOAT) )
    actor->z = actor->floorz;
    return true;
}


//
// TryWalk
// Attempts to move actor on
// in its current (ob->moveangle) direction.
// If blocked by either a wall or an actor
// returns FALSE
// If move is either clear or blocked only by a door,
// returns TRUE and sets...
// If a door is in the way,
// an OpenDoor call is made to start it opening.
//
boolean P_TryWalk (mobj_t* actor)
{
    if (!P_Move (actor))
    {
    return false;
    }

    actor->movecount = P_Random()&15;
    return true;
}




void P_NewChaseDir (mobj_t* actor)
{
    fixed_t deltax;
    fixed_t deltay;

    dirtype_t   d[3];

    int     tdir;
    dirtype_t   olddir;

    dirtype_t   turnaround;

    if (!actor->target)
    I_Error ("P_NewChaseDir: called with no target");

    olddir = actor->movedir;
    turnaround=opposite[olddir];

    deltax = actor->target->x - actor->x;
    deltay = actor->target->y - actor->y;

    if (deltax>10*FRACUNIT)
    d[1]= DI_EAST;
    else if (deltax<-10*FRACUNIT)
    d[1]= DI_WEST;
    else
    d[1]=DI_NODIR;

    if (deltay<-10*FRACUNIT)
    d[2]= DI_SOUTH;
    else if (deltay>10*FRACUNIT)
    d[2]= DI_NORTH;
    else
    d[2]=DI_NODIR;

    // try direct route
    if (d[1] != DI_NODIR
    && d[2] != DI_NODIR)
    {
    actor->movedir = diags[((deltay<0)<<1)+(deltax>0)];
    if (actor->movedir != (int) turnaround && P_TryWalk(actor))
        return;
    }

    // try other directions
    if (P_Random() > 200
    ||  abs(deltay)>abs(deltax))
    {
    tdir=d[1];
    d[1]=d[2];
    d[2]=tdir;
    }

    if (d[1]==turnaround)
    d[1]=DI_NODIR;
    if (d[2]==turnaround)
    d[2]=DI_NODIR;

    if (d[1]!=DI_NODIR)
    {
    actor->movedir = d[1];
    if (P_TryWalk(actor))
    {
        // either moved forward or attacked
        return;
    }
    }

    if (d[2]!=DI_NODIR)
    {
    actor->movedir =d[2];

    if (P_TryWalk(actor))
        return;
    }

    // there is no direct path to the player,
    // so pick another direction.
    if (olddir!=DI_NODIR)
    {
    actor->movedir =olddir;

    if (P_TryWalk(actor))
        return;
    }

    // randomly determine direction of search
    if (P_Random()&1)
    {
    for ( tdir=DI_EAST;
          tdir<=DI_SOUTHEAST;
          tdir++ )
    {
        if (tdir != (int) turnaround)
        {
        actor->movedir =tdir;

        if ( P_TryWalk(actor) )
            return;
        }
    }
    }
    else
    {
    for ( tdir=DI_SOUTHEAST;
          tdir != (DI_EAST-1);
          tdir-- )
    {
        if (tdir != (int) turnaround)
        {
        actor->movedir = tdir;

        if ( P_TryWalk(actor) )
            return;
        }
    }
    }

    if (turnaround !=  DI_NODIR)
    {
    actor->movedir =turnaround;
    if ( P_TryWalk(actor) )
        return;
    }

    actor->movedir = DI_NODIR;  // can not move
}



//
// P_LookForPlayers
// If allaround is false, only look 180 degrees in front.
// Returns true if a player is targeted.
//
boolean
P_LookForPlayers
( mobj_t*   actor,
  boolean   allaround )
{
    int     c;
    int     stop;
    player_t*   player;
    angle_t an;
    fixed_t dist;

    c = 0;
    stop = (actor->lastlook-1)&3;

    for ( ; ; actor->lastlook = (actor->lastlook+1)&3 )
    {
    if (!playeringame[actor->lastlook])
        continue;

    if (c++ == 2
        || actor->lastlook == stop)
    {
        // done looking
        return false;
    }

    player = &players[actor->lastlook];

    if (player->health <= 0)
        continue;       // dead

    if (!P_CheckSight (actor, player->mo))
        continue;       // out of sight

    if (!allaround)
    {
        an = R_PointToAngle2 (actor->x,
                  actor->y,
                  player->mo->x,
                  player->mo->y)
        - actor->angle;

        if (an > ANG90 && an < ANG270)
        {
        dist = P_AproxDistance (player->mo->x - actor->x,
                    player->mo->y - actor->y);
        // if real close, react anyway
        if (dist > MELEERANGE)
            continue;   // behind back
        }
    }

    actor->target = player->mo;
    return true;
    }

    return false;
}


//
// A_KeenDie
// DOOM II special, map 32.
// Uses special tag 666.
//
void A_KeenDie (mobj_t* mo)
{
    thinker_t*  th;
    mobj_t* mo2;
    line_t  junk;

    A_Fall (mo);

    // scan the remaining thinkers
    // to see if all Keens are dead
    for (th = thinkercap.next ; th != &thinkercap ; th=th->next)
    {
    if (th->function.acp1 != (actionf_p1)P_MobjThinker)
        continue;

    mo2 = (mobj_t *)th;
    if (mo2 != mo
        && mo2->type == mo->type
        && mo2->health > 0)
    {
        // other Keen not dead
        return;
    }
    }

    junk.tag = 666;
    EV_DoDoor(&junk, vld_open);
}


//
// ACTION ROUTINES
//

//
// A_Look
// Stay in state until a player is sighted.
//
void A_Look (mobj_t* actor)
{
    mobj_t* targ;

    actor->threshold = 0;   // any shot will wake up
    targ = actor->subsector->sector->soundtarget;

    if (targ
    && (targ->flags & MF_SHOOTABLE) )
    {
    actor->target = targ;

    if ( actor->flags & MF_AMBUSH )
    {
        if (P_CheckSight (actor, actor->target))
        goto seeyou;
    }
    else
        goto seeyou;
    }


    if (!P_LookForPlayers (actor, false) )
    return;

    // go into chase state
  seeyou:
    if (actor->info->seesound)
    {
    int     sound;

    switch (actor->info->seesound)
    {
      case sfx_posit1:
      case sfx_posit2:
      case sfx_posit3:
        sound = sfx_posit1+P_Random()%3;
        break;

      case sfx_bgsit1:
      case sfx_bgsit2:
        sound = sfx_bgsit1+P_Random()%2;
        break;

      default:
        sound = actor->info->seesound;
        break;
    }

    if (actor->type==MT_SPIDER
        || actor->type == MT_CYBORG)
    {
        // full volume
        S_StartSound (NULL, sound);
    }
    else
        S_StartSound (actor, sound);
    }

    P_SetMobjState (actor, actor->info->seestate);
}


//
// A_Chase
// Actor has a melee attack,
// so it tries to close as fast as possible
//
void A_Chase (mobj_t*   actor)
{
    int     delta;

    if (actor->reactiontime)
    actor->reactiontime--;


    // modify target threshold
    if  (actor->threshold)
    {
    if (!actor->target
        || actor->target->health <= 0)
    {
        actor->threshold = 0;
    }
    else
        actor->threshold--;
    }

    // turn towards movement direction if not there yet
    if (actor->movedir < 8)
    {
    actor->angle &= (7<<29);
    delta = actor->angle - (actor->movedir << 29);

    if (delta > 0)
        actor->angle -= ANG90/2;
    else if (delta < 0)
        actor->angle += ANG90/2;
    }

    if (!actor->target
    || !(actor->target->flags&MF_SHOOTABLE))
    {
    // look for a new target
    if (P_LookForPlayers(actor,true))
        return;     // got a new target

    P_SetMobjState (actor, actor->info->spawnstate);
    return;
    }

    // do not attack twice in a row
    if (actor->flags & MF_JUSTATTACKED)
    {
    actor->flags &= ~MF_JUSTATTACKED;
    if (gameskill != sk_nightmare && !fastparm)
        P_NewChaseDir (actor);
    return;
    }

    // check for melee attack
    if (actor->info->meleestate
    && P_CheckMeleeRange (actor))
    {
    if (actor->info->attacksound)
        S_StartSound (actor, actor->info->attacksound);

    P_SetMobjState (actor, actor->info->meleestate);
    return;
    }

    // check for missile attack
    if (actor->info->missilestate)
    {
    if (gameskill < sk_nightmare
        && !fastparm && actor->movecount)
    {
        goto nomissile;
    }

    if (!P_CheckMissileRange (actor))
        goto nomissile;

    P_SetMobjState (actor, actor->info->missilestate);
    actor->flags |= MF_JUSTATTACKED;
    return;
    }

    // ?
  nomissile:
    // possibly choose another target
    if (netgame
    && !actor->threshold
    && !P_CheckSight (actor, actor->target) )
    {
    if (P_LookForPlayers(actor,true))
        return; // got a new target
    }

    // chase towards player
    if (--actor->movecount<0
    || !P_Move (actor))
    {
    P_NewChaseDir (actor);
    }

    // make active sound
    if (actor->info->activesound
    && P_Random () < 3)
    {
    S_StartSound (actor, actor->info->activesound);
    }
}


//
// A_FaceTarget
//
void A_FaceTarget (mobj_t* actor)
{
    if (!actor->target)
    return;

    actor->flags &= ~MF_AMBUSH;

    actor->angle = R_PointToAngle2 (actor->x,
                    actor->y,
                    actor->target->x,
                    actor->target->y);

    if (actor->target->flags & MF_SHADOW)
    actor->angle += (P_Random()-P_Random())<<21;
}


//
// A_PosAttack
//
void A_PosAttack (mobj_t* actor)
{
    int     angle;
    int     damage;
    int     slope;

    if (!actor->target)
    return;

    A_FaceTarget (actor);
    angle = actor->angle;
    slope = P_AimLineAttack (actor, angle, MISSILERANGE);

    S_StartSound (actor, sfx_pistol);
    angle += (P_Random()-P_Random())<<20;
    damage = ((P_Random()%5)+1)*3;
    P_LineAttack (actor, angle, MISSILERANGE, slope, damage);
}

void A_SPosAttack (mobj_t* actor)
{
    int     i;
    int     angle;
    int     bangle;
    int     damage;
    int     slope;

    if (!actor->target)
    return;

    S_StartSound (actor, sfx_shotgn);
    A_FaceTarget (actor);
    bangle = actor->angle;
    slope = P_AimLineAttack (actor, bangle, MISSILERANGE);

    for (i=0 ; i<3 ; i++)
    {
    angle = bangle + ((P_Random()-P_Random())<<20);
    damage = ((P_Random()%5)+1)*3;
    P_LineAttack (actor, angle, MISSILERANGE, slope, damage);
    }
}

void A_CPosAttack (mobj_t* actor)
{
    int     angle;
    int     bangle;
    int     damage;
    int     slope;

    if (!actor->target)
    return;

    S_StartSound (actor, sfx_shotgn);
    A_FaceTarget (actor);
    bangle = actor->angle;
    slope = P_AimLineAttack (actor, bangle, MISSILERANGE);

    angle = bangle + ((P_Random()-P_Random())<<20);
    damage = ((P_Random()%5)+1)*3;
    P_LineAttack (actor, angle, MISSILERANGE, slope, damage);
}

void A_CPosRefire (mobj_t* actor)
{
    // keep firing unless target got out of sight
    A_FaceTarget (actor);

    if (P_Random () < 40)
    return;

    if (!actor->target
    || actor->target->health <= 0
    || !P_CheckSight (actor, actor->target) )
    {
    P_SetMobjState (actor, actor->info->seestate);
    }
}


void A_SpidRefire (mobj_t* actor)
{
    // keep firing unless target got out of sight
    A_FaceTarget (actor);

    if (P_Random () < 10)
    return;

    if (!actor->target
    || actor->target->health <= 0
    || !P_CheckSight (actor, actor->target) )
    {
    P_SetMobjState (actor, actor->info->seestate);
    }
}

void A_BspiAttack (mobj_t *actor)
{
    if (!actor->target)
    return;

    A_FaceTarget (actor);

    // launch a missile
    P_SpawnMissile (actor, actor->target, MT_ARACHPLAZ);
}


//
// A_TroopAttack
//
void A_TroopAttack (mobj_t* actor)
{
    int     damage;

    if (!actor->target)
    return;

    A_FaceTarget (actor);
    if (P_CheckMeleeRange (actor))
    {
    S_StartSound (actor, sfx_claw);
    damage = (P_Random()%8+1)*3;
    P_DamageMobj (actor->target, actor, actor, damage);
    return;
    }


    // launch a missile
    P_SpawnMissile (actor, actor->target, MT_TROOPSHOT);
}


void A_SargAttack (mobj_t* actor)
{
    int     damage;

    if (!actor->target)
    return;

    A_FaceTarget (actor);
    if (P_CheckMeleeRange (actor))
    {
    damage = ((P_Random()%10)+1)*4;
    P_DamageMobj (actor->target, actor, actor, damage);
    }
}

void A_HeadAttack (mobj_t* actor)
{
    int     damage;

    if (!actor->target)
    return;

    A_FaceTarget (actor);
    if (P_CheckMeleeRange (actor))
    {
    damage = (P_Random()%6+1)*10;
    P_DamageMobj (actor->target, actor, actor, damage);
    return;
    }

    // launch a missile
    P_SpawnMissile (actor, actor->target, MT_HEADSHOT);
}

void A_CyberAttack (mobj_t* actor)
{
    if (!actor->target)
    return;

    A_FaceTarget (actor);
    P_SpawnMissile (actor, actor->target, MT_ROCKET);
}


void A_BruisAttack (mobj_t* actor)
{
    int     damage;

    if (!actor->target)
    return;

    if (P_CheckMeleeRange (actor))
    {
    S_StartSound (actor, sfx_claw);
    damage = (P_Random()%8+1)*10;
    P_DamageMobj (actor->target, actor, actor, damage);
    return;
    }

    // launch a missile
    P_SpawnMissile (actor, actor->target, MT_BRUISERSHOT);
}


//
// A_SkelMissile
//
void A_SkelMissile (mobj_t* actor)
{
    mobj_t* mo;

    if (!actor->target)
    return;

    A_FaceTarget (actor);
    actor->z += 16*FRACUNIT;    // so missile spawns higher
    mo = P_SpawnMissile (actor, actor->target, MT_TRACER);
    actor->z -= 16*FRACUNIT;    // back to normal

    mo->x += mo->momx;
    mo->y += mo->momy;
    mo->tracer = actor->target;
}

int TRACEANGLE = 0xc000000;

void A_Tracer (mobj_t* actor)
{
    angle_t exact;
    fixed_t dist;
    fixed_t slope;
    mobj_t* dest;
    mobj_t* th;

    if (gametic & 3)
    return;

    // spawn a puff of smoke behind the rocket
    P_SpawnPuff (actor->x, actor->y, actor->z);

    th = P_SpawnMobj (actor->x-actor->momx,
              actor->y-actor->momy,
              actor->z, MT_SMOKE);

    th->momz = FRACUNIT;
    th->tics -= P_Random()&3;
    if (th->tics < 1)
    th->tics = 1;

    // adjust direction
    dest = actor->tracer;

    if (!dest || dest->health <= 0)
    return;

    // change angle
    exact = R_PointToAngle2 (actor->x,
                 actor->y,
                 dest->x,
                 dest->y);

    if (exact != actor->angle)
    {
    if (exact - actor->angle > 0x80000000)
    {
        actor->angle -= TRACEANGLE;
        if (exact - actor->angle < 0x80000000)
        actor->angle = exact;
    }
    else
    {
        actor->angle += TRACEANGLE;
        if (exact - actor->angle > 0x80000000)
        actor->angle = exact;
    }
    }

    exact = actor->angle>>ANGLETOFINESHIFT;
    actor->momx = FixedMul (actor->info->speed, finecosine[exact]);
    actor->momy = FixedMul (actor->info->speed, finesine[exact]);

    // change slope
    dist = P_AproxDistance (dest->x - actor->x,
                dest->y - actor->y);

    dist = dist / actor->info->speed;

    if (dist < 1)
    dist = 1;
    slope = (dest->z+40*FRACUNIT - actor->z) / dist;

    if (slope < actor->momz)
    actor->momz -= FRACUNIT/8;
    else
    actor->momz += FRACUNIT/8;
}


void A_SkelWhoosh (mobj_t*  actor)
{
    if (!actor->target)
    return;
    A_FaceTarget (actor);
    S_StartSound (actor,sfx_skeswg);
}

void A_SkelFist (mobj_t*    actor)
{
    int     damage;

    if (!actor->target)
    return;

    A_FaceTarget (actor);

    if (P_CheckMeleeRange (actor))
    {
    damage = ((P_Random()%10)+1)*6;
    S_StartSound (actor, sfx_skepch);
    P_DamageMobj (actor->target, actor, actor, damage);
    }
}



//
// PIT_VileCheck
// Detect a corpse that could be raised.
//
mobj_t*     corpsehit;
mobj_t*     vileobj;
fixed_t     viletryx;
fixed_t     viletryy;

boolean PIT_VileCheck (mobj_t*  thing)
{
    int     maxdist;
    boolean check;

    if (!(thing->flags & MF_CORPSE) )
    return true;    // not a monster

    if (thing->tics != -1)
    return true;    // not lying still yet

    if (thing->info->raisestate == S_NULL)
    return true;    // monster doesn't have a raise state

    maxdist = thing->info->radius + mobjinfo[MT_VILE].radius;

    if ( abs(thing->x - viletryx) > maxdist
     || abs(thing->y - viletryy) > maxdist )
    return true;        // not actually touching

    corpsehit = thing;
    corpsehit->momx = corpsehit->momy = 0;
    corpsehit->height <<= 2;
    check = P_CheckPosition (corpsehit, corpsehit->x, corpsehit->y);
    corpsehit->height >>= 2;

    if (!check)
    return true;        // doesn't fit here

    return false;       // got one, so stop checking
}



//
// A_VileChase
// Check for ressurecting a body
//
void A_VileChase (mobj_t* actor)
{
    int         xl;
    int         xh;
    int         yl;
    int         yh;

    int         bx;
    int         by;

    mobjinfo_t*     info;
    mobj_t*     temp;

    if (actor->movedir != DI_NODIR)
    {
    // check for corpses to raise
    viletryx =
        actor->x + actor->info->speed*xspeed[actor->movedir];
    viletryy =
        actor->y + actor->info->speed*yspeed[actor->movedir];

    xl = (viletryx - bmaporgx - MAXRADIUS*2)>>MAPBLOCKSHIFT;
    xh = (viletryx - bmaporgx + MAXRADIUS*2)>>MAPBLOCKSHIFT;
    yl = (viletryy - bmaporgy - MAXRADIUS*2)>>MAPBLOCKSHIFT;
    yh = (viletryy - bmaporgy + MAXRADIUS*2)>>MAPBLOCKSHIFT;

    vileobj = actor;
    for (bx=xl ; bx<=xh ; bx++)
    {
        for (by=yl ; by<=yh ; by++)
        {
        // Call PIT_VileCheck to check
        // whether object is a corpse
        // that canbe raised.
        if (!P_BlockThingsIterator(bx,by,PIT_VileCheck))
        {
            // got one!
            temp = actor->target;
            actor->target = corpsehit;
            A_FaceTarget (actor);
            actor->target = temp;

            P_SetMobjState (actor, S_VILE_HEAL1);
            S_StartSound (corpsehit, sfx_slop);
            info = corpsehit->info;

            P_SetMobjState (corpsehit,info->raisestate);
            corpsehit->height <<= 2;
            corpsehit->flags = info->flags;
            corpsehit->health = info->spawnhealth;
            corpsehit->target = NULL;

            return;
        }
        }
    }
    }

    // Return to normal attack.
    A_Chase (actor);
}


//
// A_VileStart
//
void A_VileStart (mobj_t* actor)
{
    S_StartSound (actor, sfx_vilatk);
}


//
// A_Fire
// Keep fire in front of player unless out of sight
//
void A_Fire (mobj_t* actor);

void A_StartFire (mobj_t* actor)
{
    S_StartSound(actor,sfx_flamst);
    A_Fire(actor);
}

void A_FireCrackle (mobj_t* actor)
{
    S_StartSound(actor,sfx_flame);
    A_Fire(actor);
}

void A_Fire (mobj_t* actor)
{
    mobj_t* dest;
    mobj_t*     target;
    unsigned    an;

    dest = actor->tracer;
    if (!dest)
    return;

    target = P_SubstNullMobj(actor->target);

    // don't move it if the vile lost sight
    if (!P_CheckSight (target, dest) )
    return;

    an = dest->angle >> ANGLETOFINESHIFT;

    P_UnsetThingPosition (actor);
    actor->x = dest->x + FixedMul (24*FRACUNIT, finecosine[an]);
    actor->y = dest->y + FixedMul (24*FRACUNIT, finesine[an]);
    actor->z = dest->z;
    P_SetThingPosition (actor);
}



//
// A_VileTarget
// Spawn the hellfire
//
void A_VileTarget (mobj_t*  actor)
{
    mobj_t* fog;

    if (!actor->target)
    return;

    A_FaceTarget (actor);

    fog = P_SpawnMobj (actor->target->x,
               actor->target->x,
               actor->target->z, MT_FIRE);

    actor->tracer = fog;
    fog->target = actor;
    fog->tracer = actor->target;
    A_Fire (fog);
}




//
// A_VileAttack
//
void A_VileAttack (mobj_t* actor)
{
    mobj_t* fire;
    int     an;

    if (!actor->target)
    return;

    A_FaceTarget (actor);

    if (!P_CheckSight (actor, actor->target) )
    return;

    S_StartSound (actor, sfx_barexp);
    P_DamageMobj (actor->target, actor, actor, 20);
    actor->target->momz = 1000*FRACUNIT/actor->target->info->mass;

    an = actor->angle >> ANGLETOFINESHIFT;

    fire = actor->tracer;

    if (!fire)
    return;

    // move the fire between the vile and the player
    fire->x = actor->target->x - FixedMul (24*FRACUNIT, finecosine[an]);
    fire->y = actor->target->y - FixedMul (24*FRACUNIT, finesine[an]);
    P_RadiusAttack (fire, actor, 70 );
}




//
// Mancubus attack,
// firing three missiles (bruisers)
// in three different directions?
// Doesn't look like it.
//
#define FATSPREAD   (ANG90/8)

void A_FatRaise (mobj_t *actor)
{
    A_FaceTarget (actor);
    S_StartSound (actor, sfx_manatk);
}


void A_FatAttack1 (mobj_t* actor)
{
    mobj_t* mo;
    mobj_t*     target;
    int     an;

    A_FaceTarget (actor);

    // Change direction  to ...
    actor->angle += FATSPREAD;
    target = P_SubstNullMobj(actor->target);
    P_SpawnMissile (actor, target, MT_FATSHOT);

    mo = P_SpawnMissile (actor, target, MT_FATSHOT);
    mo->angle += FATSPREAD;
    an = mo->angle >> ANGLETOFINESHIFT;
    mo->momx = FixedMul (mo->info->speed, finecosine[an]);
    mo->momy = FixedMul (mo->info->speed, finesine[an]);
}

void A_FatAttack2 (mobj_t* actor)
{
    mobj_t* mo;
    mobj_t*     target;
    int     an;

    A_FaceTarget (actor);
    // Now here choose opposite deviation.
    actor->angle -= FATSPREAD;
    target = P_SubstNullMobj(actor->target);
    P_SpawnMissile (actor, target, MT_FATSHOT);

    mo = P_SpawnMissile (actor, target, MT_FATSHOT);
    mo->angle -= FATSPREAD*2;
    an = mo->angle >> ANGLETOFINESHIFT;
    mo->momx = FixedMul (mo->info->speed, finecosine[an]);
    mo->momy = FixedMul (mo->info->speed, finesine[an]);
}

void A_FatAttack3 (mobj_t*  actor)
{
    mobj_t* mo;
    mobj_t*     target;
    int     an;

    A_FaceTarget (actor);

    target = P_SubstNullMobj(actor->target);

    mo = P_SpawnMissile (actor, target, MT_FATSHOT);
    mo->angle -= FATSPREAD/2;
    an = mo->angle >> ANGLETOFINESHIFT;
    mo->momx = FixedMul (mo->info->speed, finecosine[an]);
    mo->momy = FixedMul (mo->info->speed, finesine[an]);

    mo = P_SpawnMissile (actor, target, MT_FATSHOT);
    mo->angle += FATSPREAD/2;
    an = mo->angle >> ANGLETOFINESHIFT;
    mo->momx = FixedMul (mo->info->speed, finecosine[an]);
    mo->momy = FixedMul (mo->info->speed, finesine[an]);
}


//
// SkullAttack
// Fly at the player like a missile.
//
#define SKULLSPEED      (20*FRACUNIT)

void A_SkullAttack (mobj_t* actor)
{
    mobj_t*     dest;
    angle_t     an;
    int         dist;

    if (!actor->target)
    return;

    dest = actor->target;
    actor->flags |= MF_SKULLFLY;

    S_StartSound (actor, actor->info->attacksound);
    A_FaceTarget (actor);
    an = actor->angle >> ANGLETOFINESHIFT;
    actor->momx = FixedMul (SKULLSPEED, finecosine[an]);
    actor->momy = FixedMul (SKULLSPEED, finesine[an]);
    dist = P_AproxDistance (dest->x - actor->x, dest->y - actor->y);
    dist = dist / SKULLSPEED;

    if (dist < 1)
    dist = 1;
    actor->momz = (dest->z+(dest->height>>1) - actor->z) / dist;
}


//
// A_PainShootSkull
// Spawn a lost soul and launch it at the target
//
void
A_PainShootSkull
( mobj_t*   actor,
  angle_t   angle )
{
    fixed_t x;
    fixed_t y;
    fixed_t z;

    mobj_t* newmobj;
    angle_t an;
    int     prestep;
    int     count;
    thinker_t*  currentthinker;

    // count total number of skull currently on the level
    count = 0;

    currentthinker = thinkercap.next;
    while (currentthinker != &thinkercap)
    {
    if (   (currentthinker->function.acp1 == (actionf_p1)P_MobjThinker)
        && ((mobj_t *)currentthinker)->type == MT_SKULL)
        count++;
    currentthinker = currentthinker->next;
    }

    // if there are allready 20 skulls on the level,
    // don't spit another one
    if (count > 20)
    return;


    // okay, there's playe for another one
    an = angle >> ANGLETOFINESHIFT;

    prestep =
    4*FRACUNIT
    + 3*(actor->info->radius + mobjinfo[MT_SKULL].radius)/2;

    x = actor->x + FixedMul (prestep, finecosine[an]);
    y = actor->y + FixedMul (prestep, finesine[an]);
    z = actor->z + 8*FRACUNIT;

    newmobj = P_SpawnMobj (x , y, z, MT_SKULL);

    // Check for movements.
    if (!P_TryMove (newmobj, newmobj->x, newmobj->y))
    {
    // kill it immediately
    P_DamageMobj (newmobj,actor,actor,10000);
    return;
    }

    newmobj->target = actor->target;
    A_SkullAttack (newmobj);
}


//
// A_PainAttack
// Spawn a lost soul and launch it at the target
//
void A_PainAttack (mobj_t* actor)
{
    if (!actor->target)
    return;

    A_FaceTarget (actor);
    A_PainShootSkull (actor, actor->angle);
}


void A_PainDie (mobj_t* actor)
{
    A_Fall (actor);
    A_PainShootSkull (actor, actor->angle+ANG90);
    A_PainShootSkull (actor, actor->angle+ANG180);
    A_PainShootSkull (actor, actor->angle+ANG270);
}






void A_Scream (mobj_t* actor)
{
    int     sound;

    switch (actor->info->deathsound)
    {
      case 0:
    return;

      case sfx_podth1:
      case sfx_podth2:
      case sfx_podth3:
    sound = sfx_podth1 + P_Random ()%3;
    break;

      case sfx_bgdth1:
      case sfx_bgdth2:
    sound = sfx_bgdth1 + P_Random ()%2;
    break;

      default:
    sound = actor->info->deathsound;
    break;
    }

    // Check for bosses.
    if (actor->type==MT_SPIDER
    || actor->type == MT_CYBORG)
    {
    // full volume
    S_StartSound (NULL, sound);
    }
    else
    S_StartSound (actor, sound);
}


void A_XScream (mobj_t* actor)
{
    S_StartSound (actor, sfx_slop);
}

void A_Pain (mobj_t* actor)
{
    if (actor->info->painsound)
    S_StartSound (actor, actor->info->painsound);
}



void A_Fall (mobj_t *actor)
{
    // actor is on ground, it can be walked over
    actor->flags &= ~MF_SOLID;

    // So change this if corpse objects
    // are meant to be obstacles.
}


//
// A_Explode
//
void A_Explode (mobj_t* thingy)
{
    P_RadiusAttack(thingy, thingy->target, 128);
}

// Check whether the death of the specified monster type is allowed
// to trigger the end of episode special action.
//
// This behavior changed in v1.9, the most notable effect of which
// was to break uac_dead.wad

static boolean CheckBossEnd(mobjtype_t motype)
{
    if (gameversion < exe_ultimate)
    {
        if (gamemap != 8)
        {
            return false;
        }

        // Baron death on later episodes is nothing special.

        if (motype == MT_BRUISER && gameepisode != 1)
        {
            return false;
        }

        return true;
    }
    else
    {
        // New logic that appeared in Ultimate Doom.
        // Looks like the logic was overhauled while adding in the
        // episode 4 support.  Now bosses only trigger on their
        // specific episode.

    switch(gameepisode)
    {
            case 1:
                return gamemap == 8 && motype == MT_BRUISER;

            case 2:
                return gamemap == 8 && motype == MT_CYBORG;

            case 3:
                return gamemap == 8 && motype == MT_SPIDER;

        case 4:
                return (gamemap == 6 && motype == MT_CYBORG)
                    || (gamemap == 8 && motype == MT_SPIDER);

            default:
                return gamemap == 8;
    }
    }
}

//
// A_BossDeath
// Possibly trigger special effects
// if on first boss level
//
void A_BossDeath (mobj_t* mo)
{
    thinker_t*  th;
    mobj_t* mo2;
    line_t  junk;
    int     i;

    if ( gamemode == commercial)
    {
    if (gamemap != 7)
        return;

    if ((mo->type != MT_FATSO)
        && (mo->type != MT_BABY))
        return;
    }
    else
    {
        if (!CheckBossEnd(mo->type))
        {
            return;
        }
    }

    // make sure there is a player alive for victory
    for (i=0 ; i<MAXPLAYERS ; i++)
    if (playeringame[i] && players[i].health > 0)
        break;

    if (i==MAXPLAYERS)
    return; // no one left alive, so do not end game

    // scan the remaining thinkers to see
    // if all bosses are dead
    for (th = thinkercap.next ; th != &thinkercap ; th=th->next)
    {
    if (th->function.acp1 != (actionf_p1)P_MobjThinker)
        continue;

    mo2 = (mobj_t *)th;
    if (mo2 != mo
        && mo2->type == mo->type
        && mo2->health > 0)
    {
        // other boss not dead
        return;
    }
    }

    // victory!
    if ( gamemode == commercial)
    {
    if (gamemap == 7)
    {
        if (mo->type == MT_FATSO)
        {
        junk.tag = 666;
        EV_DoFloor(&junk,lowerFloorToLowest);
        return;
        }

        if (mo->type == MT_BABY)
        {
        junk.tag = 667;
        EV_DoFloor(&junk,raiseToTexture);
        return;
        }
    }
    }
    else
    {
    switch(gameepisode)
    {
      case 1:
        junk.tag = 666;
        EV_DoFloor (&junk, lowerFloorToLowest);
        return;
        break;

      case 4:
        switch(gamemap)
        {
          case 6:
        junk.tag = 666;
        EV_DoDoor (&junk, vld_blazeOpen);
        return;
        break;

          case 8:
        junk.tag = 666;
        EV_DoFloor (&junk, lowerFloorToLowest);
        return;
        break;
        }
    }
    }

    G_ExitLevel ();
}


void A_Hoof (mobj_t* mo)
{
    S_StartSound (mo, sfx_hoof);
    A_Chase (mo);
}

void A_Metal (mobj_t* mo)
{
    S_StartSound (mo, sfx_metal);
    A_Chase (mo);
}

void A_BabyMetal (mobj_t* mo)
{
    S_StartSound (mo, sfx_bspwlk);
    A_Chase (mo);
}

void
A_OpenShotgun2
( player_t* player,
  pspdef_t* psp )
{
    S_StartSound (player->mo, sfx_dbopn);
}

void
A_LoadShotgun2
( player_t* player,
  pspdef_t* psp )
{
    S_StartSound (player->mo, sfx_dbload);
}

void
A_ReFire
( player_t* player,
  pspdef_t* psp );

void
A_CloseShotgun2
( player_t* player,
  pspdef_t* psp )
{
    S_StartSound (player->mo, sfx_dbcls);
    A_ReFire(player,psp);
}



mobj_t*     braintargets[32];
int     numbraintargets;
int     braintargeton = 0;

void A_BrainAwake (mobj_t* mo)
{
    thinker_t*  thinker;
    mobj_t* m;

    // find all the target spots
    numbraintargets = 0;
    braintargeton = 0;

    thinker = thinkercap.next;
    for (thinker = thinkercap.next ;
     thinker != &thinkercap ;
     thinker = thinker->next)
    {
    if (thinker->function.acp1 != (actionf_p1)P_MobjThinker)
        continue;   // not a mobj

    m = (mobj_t *)thinker;

    if (m->type == MT_BOSSTARGET )
    {
        braintargets[numbraintargets] = m;
        numbraintargets++;
    }
    }

    S_StartSound (NULL,sfx_bossit);
}


void A_BrainPain (mobj_t*   mo)
{
    S_StartSound (NULL,sfx_bospn);
}


void A_BrainScream (mobj_t* mo)
{
    int     x;
    int     y;
    int     z;
    mobj_t* th;

    for (x=mo->x - 196*FRACUNIT ; x< mo->x + 320*FRACUNIT ; x+= FRACUNIT*8)
    {
    y = mo->y - 320*FRACUNIT;
    z = 128 + P_Random()*2*FRACUNIT;
    th = P_SpawnMobj (x,y,z, MT_ROCKET);
    th->momz = P_Random()*512;

    P_SetMobjState (th, S_BRAINEXPLODE1);

    th->tics -= P_Random()&7;
    if (th->tics < 1)
        th->tics = 1;
    }

    S_StartSound (NULL,sfx_bosdth);
}



void A_BrainExplode (mobj_t* mo)
{
    int     x;
    int     y;
    int     z;
    mobj_t* th;

    x = mo->x + (P_Random () - P_Random ())*2048;
    y = mo->y;
    z = 128 + P_Random()*2*FRACUNIT;
    th = P_SpawnMobj (x,y,z, MT_ROCKET);
    th->momz = P_Random()*512;

    P_SetMobjState (th, S_BRAINEXPLODE1);

    th->tics -= P_Random()&7;
    if (th->tics < 1)
    th->tics = 1;
}


void A_BrainDie (mobj_t*    mo)
{
    G_ExitLevel ();
}

void A_BrainSpit (mobj_t*   mo)
{
    mobj_t* targ;
    mobj_t* newmobj;

    static int  easy = 0;

    easy ^= 1;
    if (gameskill <= sk_easy && (!easy))
    return;

    // shoot a cube at current target
    targ = braintargets[braintargeton];
    braintargeton = (braintargeton+1)%numbraintargets;

    // spawn brain missile
    newmobj = P_SpawnMissile (mo, targ, MT_SPAWNSHOT);
    newmobj->target = targ;
    newmobj->reactiontime =
    ((targ->y - mo->y)/newmobj->momy) / newmobj->state->tics;

    S_StartSound(NULL, sfx_bospit);
}



void A_SpawnFly (mobj_t* mo);

// travelling cube sound
void A_SpawnSound (mobj_t* mo)
{
    S_StartSound (mo,sfx_boscub);
    A_SpawnFly(mo);
}

void A_SpawnFly (mobj_t* mo)
{
    mobj_t* newmobj;
    mobj_t* fog;
    mobj_t* targ;
    int     r;
    mobjtype_t  type;

    if (--mo->reactiontime)
    return; // still flying

    targ = P_SubstNullMobj(mo->target);

    // First spawn teleport fog.
    fog = P_SpawnMobj (targ->x, targ->y, targ->z, MT_SPAWNFIRE);
    S_StartSound (fog, sfx_telept);

    // Randomly select monster to spawn.
    r = P_Random ();

    // Probability distribution (kind of :),
    // decreasing likelihood.
    if ( r<50 )
    type = MT_TROOP;
    else if (r<90)
    type = MT_SERGEANT;
    else if (r<120)
    type = MT_SHADOWS;
    else if (r<130)
    type = MT_PAIN;
    else if (r<160)
    type = MT_HEAD;
    else if (r<162)
    type = MT_VILE;
    else if (r<172)
    type = MT_UNDEAD;
    else if (r<192)
    type = MT_BABY;
    else if (r<222)
    type = MT_FATSO;
    else if (r<246)
    type = MT_KNIGHT;
    else
    type = MT_BRUISER;

    newmobj = P_SpawnMobj (targ->x, targ->y, targ->z, type);
    if (P_LookForPlayers (newmobj, true) )
    P_SetMobjState (newmobj, newmobj->info->seestate);

    // telefrag anything in this spot
    P_TeleportMove (newmobj, newmobj->x, newmobj->y);

    // remove self (i.e., cube).
    P_RemoveMobj (mo);
}



void A_PlayerScream (mobj_t* mo)
{
    // Default death sound.
    int     sound = sfx_pldeth;

    if ( (gamemode == commercial)
    &&  (mo->health < -50))
    {
    // IF THE PLAYER DIES
    // LESS THAN -50% WITHOUT GIBBING
    sound = sfx_pdiehi;
    }

    S_StartSound (mo, sound);
}
